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→{{header|6502 Assembly}}
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<lang 6502asm>INC $2005 ;the intent was to scroll the NES's screen to the right one pixel. That's not gonna happen.
;What actually happens? Who knows! (I made this mistake once long ago.)</lang>
===Inverted Carry===
The carry flag is "backwards" compared to most languages with regard to comparisons and subtractions.
On most CPUs, carry set is used to mean "less than", and carry clear is used to mean "greater than or equal." The 6502 is the opposite!
<lang 6502asm>LDA #$20
CMP #$19
BCS foo ;this branch is always taken, since #$20 >= #$19. If this were any other CPU this branch would never be taken!</lang>
Not only that, carry clear indicates a borrow when subtracting. This is also the opposite to most CPUs. To do a normal subtraction you need to ''set'' the carry before subtracting.
<lang 6502asm>LDA #8
SEC
SBC #4 ;eight minus four</lang>
=={{header|68000 Assembly}}==
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